Voltage regulation for generators



, June 2, 1925. 1,540,698

B. M. LEECE VOLTAGE REGULATION FOR GENERATORS Filed Dec. 10, 1923Patented June 2, 1925.

UNITED STATES v 1 1,540,698 PATENT OFFICE.

BENNETT M. LEECE, OF CLEVELAND, OHIO, ASSIGNO'R TO THE LEECE-NEVILLECOM- PANY, OF CLEVELAND, OHIO, A. CORPORATION OF OHIO.

VOLTAGE REGULATION FOR GENERATORS.

Application filed December 10, 1923. Serial No. 679,575.

To all whom it may concern:

a citizen of the United States, residing at Cleveland, in the county ofCuyahoga and 5 State of Ohio, have invented a certain new and usefulImprovement in Voltage Regulation for Generators, of which the followinis a full, clear, and exact description.

his invention relates to voltage regul0 lators for dynamo electricmachines and is especially adapted for li hting generators of motorvehicles wherein the speed and load vary very materially. The chiefobject of the present invention is to provide a regulator which has thede sired sensitiveness, maintaining the generator voltage at the desiredvalue, or within the desired range of variation as the speed and loadvary between maximum and minimum conditions, and which at the same timedoes not require delicate adjustments, and is more rugged than voltageregulators heretofore utilized, and is especially adaptable for severeservice conditions for which the other regulators are unsuited, as, forexample, in connection with lighting generators on motor driven busses.

The above and other objects are accomplished by my invention which maybehere briefly summarized as consisting in certain novel details ofconstruction, and combinations and arrangements of parts which will bedescribed in the specification and pointed out in the appended claims.The single fi'gure of the drawing illustrates diagrammatically oneembodiment of the invention.

My invention has proven to be particularly useful in connection withgenerators of the third brush type, and for that reason I haveillustrated the invention applied to a third brush generator, thatillustrated having an armature 10, main brushes 11 and 12, and anauxiliary or third brush l3 which is adjustable between, the mainbrushes and a field winding 14 connected between the main brush 11 andauxiliary brush 13. a g

The regulator is provided with a vibrating blade 15 adapted to move intoand out of engagement at ahigh rate with astationary contact 16, thecontacts serving to alternately increase and decrease the resistance ofthe field circuit, and in this instance to cut a resistance17 into andout of the field circuit by alternately opening and closing a shortcircuiting path around it- Let it be assumed that the main brush 11 is apositive brush, and the main brush 12 is a negative brush, then'thefield circuit is from positive brush 11 by conductor 18 throug theresistance when the contacts are open, or across the contacts around theI resistance when the contacts are closed, and

by way a conductor 19 through the field winding 14, and by a conductor20 to the auxiliary brush 13.

In carrying out my invention I utilize two vibrator coils 21 and 22, oneof these coils, in this instance, the coil 21, being con nected acrossthe main terminals of the generator so as to be responsive to changes involtage of the machine, this coil having a circuit which is constantlyclosed, or is unaffected by the action of the regulator; In thisinstance, one terminal of the coil 21 is connected to the conductor 18leading to the positive brush 11, and the other terminal is connectedbyconductor 23 to the negative brush 12.

The other c0i1'22 is connected differently to the terminals of thegenerator, and its circuit is opened and closed, or at least varied bythe vibration of the-contacts.

The effect of the two coils are additive in the core of the vibrator,the coil 22 having for its chief function to cause the movable contactmember to vibrate, while the chief function of the coil 21 is to respondto voltage changes in the generator to increase or decrease the rate ofvibration In the application of my invention-herein illustrated, it willbe'observed that when the contacts are closed, the coil 22 is connectedacross the main terminals of the generator, thecireuitthen being frompositive brush 11 by conductor 18 to the contacts, by conductor 24,which connects one ter minal of the coil and the stationary contact, 16,and by way-of conductor 23 to which the other termlnal of the coil isconnected to the negative brush 12. Likewise it will be observedthat'when the contacts are open, the coil 22 is in 'a circuit subjecttothe' potential drop between brushes 11 and 13, 1. e. the circuitcontaining the field windin but this difference of potential has a. tene ncy to reverse the current flow in coil 22 over the direction of flowwhen the contacts are closed, the effect of which is to quickly to thevoltage of de-energize this coil following the opening of the contacts.Whether or not current will flow through the coil 22 in the reversedirection will depend primarily upon the relative resistance of thecoils 21 and 22, on the one hand, and the resistance 17 onthe other andpossibly on changes in the relative polarity of the brushes 12and 13under varying conditions of load and. speed, but in any event, on theopenin 'of the contacts 16 there is a difierence 0 potential or a forcetending to reverse the current flow, and therefore to de-energize thecoil as soon as the contacts are '0 ned. As this regulator is at presentemp oyed by me with very good results, the ohmic value of resistance 17is less than that of coil 22, but the resistances of hese parts'may bedifierently proportioned, and in some instances the resist ance 17 maybe omitted entirely, in which event the coil 22 will serve its purpose,for as explained above, when the contacts are open, this coil is in thefield circuit across the contacts.

It will be seen, therefore, that my improved regulator comprises. twocoils which have a combined effect u n the vibrator blade to o n andclose t e circuit which varies the eld resistance, and that one of thesecoils is constantly energized and subjected the machine, themagnetization of the regulator core due to this coil, varying as themachine voltage varies, and that the other coil which relieves the coil21 of the function of causing the vibratin member to vibrate has itscircuit opene 'and closed at a'rate which is varied by the I one 'isshown on the drawings at 26.

action of coil 21. Further, it will be observed that by reason of thefact that when the contacts are open, the voltage between one of themain and the auxiliary brush is impressed u on the coil 22 tending topro duce reverse of current therein; The action of the vibrator ispositive and rapid, and the slu gish action which is undesirable in a reator is avoided without requiring delicate adjustments so frequentlynecemry.

For example, I am enabled to employ a much stiffer spring,indicated inthe drawing at 25, than is generally possible in re lators such as areemployed on motor vehic es, and this has the advantage that theregulator is not afiected by vibration of the vehicle,-

in consequence of which the device is well adaptedfor use on vehiclestraveling over rough roads or. at high rates of speed.Furthermore,-;with my improved regulator there is almost'com lete asence of sparking at the contacts.

fact, the use of a condenser across the contacts is unnecessary though acondenser is preferably employed, Fand urthe vibrator blade vibrates atsuch load is there is thermore,

a high speed that when the lam thrown on the light is steady an thecontacts,

to the precise details or arrangements shown,

either as to the regulator itself or to the type of-generator to whichthe regulator is applied, and I aim, therefore, to cover allmodifications which do not involve a departure from the spirit andscopeof the invention as defined in the appended claims. Having described myinvention, I claim: 1. In combination with a variable speed, variableload generator having a field circuit, a regulator for varying the fieldexcitation comprising two relatively movable contacts and twocoils, oneof the latter being connected tothe generator independently of andtheother being connected to the generator through the contacts when thelatter are closed, and said second mentioned coil having another,connection with the generator independently of the contacts. 2. Incombination with a variable speed, variable load generator having afield circuit, a regulator for varying the field excitation comprising aresistance adapted to be cut'into and out of the field circuit, a pairof contacts for short circuitin the resistance, and two coils oneconnecte to the generator independently of the contacts, and the otherbeing connected to the generator through the contacts when the latterare closed, and-having another connection with the generator in parallelrelation with said resistance and independently of the contacts. p v

3. In combination with a variable speed, variable load generator havingbrushes and a field circuit, a regulator for varying the fieldexcitation comprising a vibrating member and two contacts, and a coilconnected to the contacts and having two connections with the generatorso as to be subjected to the voltage of the enerator when the contactsare closed and to a voltage from the generator tending to reverse thecurrent flow therethrough when the contacts are opened. 4. Incombination with a variable speed, variable load generator havingbrushes and a field winding with its terminals connected to the brushes,a regulator comprising 2. vibratin the fie d excitation, and two coils,one connected to the generator so as to be responmember and contacts forvarying and'the other having its circuit varied by the o enin andclosing of the contacts where y w en the contacts are closed the coil issubjected to a voltage causing the passage of current therethrough inone direction but when the contacts are opened the coil is subject to avoltage tending to produce current flow in a reverse direction.

5. In combination with a generator of the third brush type having mainbrushes and an auxiliary brush, a field winding connected between a mainbrush and the auxiliary brush, a regulator for varying the fieldexcitation comprising a vibrating member and contacts, and two coils,one coil being connected between the main brushes, and the other beingconnected to the brushes so as to be subject to the difference ofpotential betweenone pair of the same when the contacts are closed andso as to be subject to the diiference of potential between another pairwhen the contacts are open. W

6. In combination with a generator of the third brush type having mainbrushes and an intermediate auxiliary brush, a field winding connectedbetween one of the main and the auxiliary brush, a regulator for varyingthe field excitation comprising a vibrating member and contacts, and twocoils, one coil being in a circuit connected to the main brushes, andthe other coil having a connection across the contacts with the mainbrushes, and having a connection around the contacts between one of themain'and the auxiliary brush when the contacts are 0 en.

7. In combination with a generator of the third brush type having mainbrushes and an intermediate auxiliary brush, a field winding connectedbetween one of the main and the auxiliary brush, a regulator for varyingthe field excitation comprising a vibrating member and contacts, and twocoils, one coil being in a circuit connected to the main brushes,and'the other coil having a connection across the contacts with the mainbrushes, and having a connection around the contacts through the fieldwinding when the contacts are open.

8. In combination with a variable speed, variable load generator of thethird brush type having an armature, two main brushes and an auxiliarybrush, and a field winding connected to one of the main brushes and tothe auxiliary brush, a regulator comprising avibratory element withcontacts, and two coils, one connected to the armature independently ofthe contacts so that its circuit is unaffected thereby, and meansconnecting the other regulator coil to the armature t0 operativelyassociate said coil and the field winding with the contacts so that thema netizing effects of the coil and winding W1 1 be altered on theopening and closing of the contacts, and said coil being connected to adifferent pair of brushes than the field windmg. 1

9. In combination with a variable speed, variable load generator havingan armature,

two main brushes and an intermediate third brush, and a field winding,the latter being connected to one of the main brushes and to theauxiliary brush, a voltage regulator comprising a vibratory element withassociated contacts, and two coils, both being connected to the mainbrushes, one inde-' pendently of the contacts, and means connecting theother coil and field winding to the contacts so that the magnetizingeliects thereof are-varied by the operation of the contacts.

10. In combination with a variable speed, variable load generator of thethird brush type having an armature, two main brushes and an auxiliarybrush, and a field winding connected to one of the main brushes and tothe auxiliary brush, a regulator comprising a vibratory element withcontacts, and two coils, one connected to the armature independently ofthe contacts so that its circuit is unaltered by the action of theregulator, and means connecting the other regulator coil to the armatureindependently of the field winding, said coil and the field windingbeing operatively associated with the contacts so that the magnetizingeffects of the coil and winding will be altered on the opening andclosing of the contacts.

In testimony whereof, I hereunto afiix my signature.

BENNETT M. LEECE.

